Sodium Hydroxide → 4-Fluoro-2-methoxypyridine

Temperature

10 °C

A solution containing 3.6 g of 4-amino-2-methoxypyridine in 15 ml of 48% fluoroboric acid is cooled to 10° C. 3 g of sodium nitrite are added in small portions at a temperature below -5° C. and the mixture is then stirred for 45 minutes at 0° C. It is brought slowly to room temperature and then stirred in a water bath for 30 minutes. It is cooled to -10° C. and then neutralized by the addition of 3M sodium hydroxide solution while being kept at low temperature. The mixture is extracted with 50 ml of ethyl ether and the organic phase is washed with 5 ml of cold water and dried over anhydrous potassium fluoride. The ether is distilled at atmospheric pressure. The oily residue is used as such in the next step.

1. customis brought slowly to room temperature
2. stirringstirred in a water bath for 30 minutes
3. temperatureIt is cooled to -10° C.
4. extractionThe mixture is extracted with 50 ml of ethyl ether
5. washthe organic phase is washed with 5 ml of cold water
6. dry with materialdried over anhydrous potassium fluoride
7. distillationThe ether is distilled at atmospheric pressure

ORD record

ord-3fd6903e85f64842b57860345ce6f5aa

Source dataset

uspto-grants-1994_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05284838